the victims. ceremonies in new york, virginia, and pennsylvania pay tribute to the victims killed when terrorists hijacked four commercial planes. in lower manhattan, 9/11 families gather at the park adjacent to ground zero. the names of victims will be read throughout the morning. four moments of silence will mark the times each plane had, and each tower fell. vice-president joe biden is attending. at the pentagon, president obama participated in a wreath laying ceremony. in pennsylvania, were united flight 93 crash, first lady michelle obama and laura bullish attend a ceremony. plans to improve at ground zero are moving forward. it is scheduled to be completed by 2013. with each step forward, there remains a connection to the test -- steel beams pulled from the rubble or permanently installed this week at the museum, slated to be finished in 2012. >> it will be a memorial that we will all be proud of and inspire people around the world. >> and always remind them never to forget. tonight, was always -- was also become a tradition -- twin beams in eliminating the sky. >> that her attac